The present invention relates to powder material compacting presses, more particularly to an improved die and punch assembly for powder compacting presses.
In powder compacting presses as disclosed in U.S. Pat. Nos. 3,328,840; 3,344,213, 3,328,842; 3,414,940; 3,561,054; 3,726,622; 3,741,697; 3,775,032; 3,805,370 and 3,822,974, all assigned to the same assignee as the present application, there are disclosed apparatus such as presses and tools for such presses for compacting powder material, such as powdered metal, ferrite, glass and other materials into diverse articles such as toroids, beads, pellets and the like. In the powder compacting apparatus disclosed in the aforementioned patents, the articles are formed in single or multi-cavity dies, in which reciprocable punches are disposed, by compaction of the powder material between the punch end face and an anvil displaceable over the die cavity so as to overlap the die cavity.
A work station positioner assembly, forming part of the press apparatus, is disposed angularly or linearly movable over the die plate and is provided with three separate or integral elements, a powder dispenser unit, an anvil, and a pick-up head. The powder dispenser unit is first positioned over the die cavity to fill the die cavity with a predetermined amount of powder material. The dispenser unit is then removed from above the work station positioner assembly, and the anvil unit is in turn positioned over the die cavity and clamped in position. The punch is reciprocated upwardly in the die such as to compact the powder material between the punch end face and the anvil. The anvil is then unclamped from above the die cavity and replaced by the pick-up head as a result of further angular or linear motion of the work station positioner assembly. The punch is reciprocated upwardly so as to eject the compacted article from the die cavity into the pick-up head for transfer to a remote station, or, alternatively, for transfer to a collection station by subsequent motion of the work station positioner assembly.
By way of utilizing standardized punch and die assemblies in the form of interchangeable tool capsules, all adapted to be interchangeably mounted on the press table in an appropriate mounting aperture, with the die plate disposed in the mounting aperture and held therein by any convenient means such as by mounting bolts, the remaining of the tool capsule projecting below the press table, with the punch actuating mechanism of the press appropriately connected to the punch actuating plate portion of the tool capsule, it is a simple matter after a production run of a particular part to remove a tool capsule and replace it by another tool capsule for compacting a different part. With the exception of the die bushings, the punches, and the core rods, if any, all the other mechanical parts forming the tool capsule are subject to little or no wear. The die bushings, the punch and the core rods, if any, are however, subject to important load stresses and to wear, as a result of which they may experience dimensional changes, such as a progressive opening of tolerances, and, if subjected to abnormal loads, they may be damaged beyond repair or even break. It is therefore convenient for the user to provide a tool capsule which can be easily dismantled and which provides easy removal of the die bushings, punches and core rods, when they become worn or when they break, for replacement by new die bushings, punches and core rods. It is also desirable that replacement die bushings, punches and core rods be reinserted in the tool capsule without too much fuss, without requiring complicated fixtures and gauges, and that the diverse replacement elements be held securely in position in proper alignment, as lack of alignment and incorrect positioning may result in breakage or in obtaining finished parts not conforming to specifications.